Refining of petroleum



2 Sheets-Sheet l l-ssEi E Eiiiiiiil wu' Pfl/f4- fw INVENToRs E. B. PHILLIPS ET AI.

REFINING OF PETROLEUM Filed Aug. '7, 1925 April 16, 1929.

BY www ATTORNEYS April 16, 1929- E. B. PHILLIPS ET AL 1,709,149

REFINING OF PETROLEUM Filed Aug. '7, 1923 2 Sheets-Sheet 2 jm g W INVENTORS ATTORNEYS tcrial treated; but, in addition, such acid,

Patented Apr. 16,- 1929.

UNITED STATT-:s

PATENT ori-Ica ERNEST B. PHILLIPS, OF EAST CHICAGO,

`I INDIANA, AND JAMES G. STAFFORD, OF

CHICAGO, ILLINOIS, ASSIGNORS TO SINCLAIR REFINING COMPANY, -OF CHICAGO,

ILLINOIS, A CORPORATION OF MAINE.

vaanname or PETROLEUM.

Application filed August 7, 1923. serial 10.656,181.`

has been thepracticeto select high quality crude oils as the material to be treated; and, as lon as such high quality crude oils were availale,` grades could be selected for special purposes and high grade products uniformly f made therefrom. 'Howeven with the treinendous increase in the demand for lubricants of various types coupled with the gradual exhaustion of superflue crude oils, the problem of obtaining high grade products from crude oils of lower quality becomes of increased importance. Y

Since the'beginning of the petroleum in- V'dustry, it has been the practice to refine petroleum oils with sulphuric acid by adding the acid to the raw productsein lead lined tanks called agitators where violent. agitation is produced by forcing large volumes of low pressure .air through the oil and added acid. It has also been the common practice to treat the oil subsequently with alkaline solutions in an attempt to neutralize the excess acid and acid compound. Those portions of the raw product which unite with the sulphuric acid are converted into thick tar-like masses which under the conditions of air agitation are broken up into fine particles and distributed through the entire mass. When the acid treating step is complete, small quantities of water are added to the acid oil to gather the small particles of sludge and cause them to settle when the batch has come to rest. The oil is thereafter .treated with the alkaline solution. l

The treatment of the oil with sulpliuric acid in the manner described, according to established practice, removes some, butl not all, of the objectionable constituents of the raw matreatment at the same time causes certain injuries to the oil and introduces undesirable compounds into the oil which are diiicultor impossible of removal by the subsequent alkaline treatment. The simultaneous action of acidand oxygen of the air upon the oil has an oxidizing effect which is made evident by the release of sulphur dioxide from the acid, and which results in secondary chemical reactions, the nature of which is somewhat 0b- .scure, which throw back undesirable compounds into the oil. The presence of these compounds in the acid-treated oil complicates the treating process and'calls for additional steps to bring about their removal, and it is sometimes difficult or impossible to effect complete removal of them. After the acid treated oil is' neutralized with alkaline solutions,

trouble is often met with because of the for-y mation of emulsions which can be overcome only by prolonged washing with water. The oxidizing treatment of the oil by the use` of air agitation during the acid treatment not only injures the oil but frequently increases thediiriculty of separating the acid sludge from the treated oil, and, evenV when so-called breaking Water is used, a clean separation is often difficult or impossible; while the subsequent steps in the treating process, involving the use of alkaline solutions for neutralization, are seriously interfered with and the finished productsy still carry undesirable impui-ities. These difficulties and objections of the established sulphuric acid'refining practice are particularly pronounced in the case of crude oils and residues which containasphaltic constituents, such as the average mid-continent crudes or reduced crudes; and it is difficult or impossible to refine such crude oils in the manner indicated and obtain refined oils from which high grade lubricants can be produced by the usual refinerymethods.Y

The present invention provides an improved method of refining hydrocarbon oils with sulphuric acid whereby the objections above referred to incident to the present reiinery practice are overcome, and Lthe production of high grade products is made possible; while the improved refining methodv of the present invention presents added advantages. hereinafter more'fully set forth. The presentinvention also provides an improved apparatus .for carrying out the new process. y The process of the present invention is carried out without the introduction of atmospheric air and with avoidance of'oxidation readily separated from the treated oil. The

I.et

treated oil, after the sulphuric acid treatment, is permitted to settle, and any remaining acid compounds are subsequently removed by a clay or fullers earth treatment.

The method and apparatus of the -present invention are of more or less general applicaa tion for the treatment of various grades of raw and partially refined petroleum products, and including,r crudeoils, both natural and reduced, as well as fractions and residuum produced therefrom. The invention is of particular value, however, in the refining of crude oils and residuum therefrom for the production of high grade lubricating oils, such as engine oils and cylinder stocks.

The invention will be further described in connection with the accompanying drawings illustrating the apparatus of the invention which is adapted for the practice ofthe processl of the invention. The drawings are somewhat diagrammatic and conventional in character; and it will be understood that the invention is illustrated thereby and by the accompanying description, but is not limited thereto.

lIn the accompanying drawings Fig. 1 shows an arrangement of apparatus partly in section and partly in elevation.

Fig. 2 is an enlarged vertical sectional View showing a somewhat modified construction of the treater for treating the oil with acid taken on the line 2 2 of Fig. 3.

Fig. 3 is a horizontal sectional view taken on the line 3 3 of Fig. 2, and

Figs. 4', 5 and 6 are enlarged views showing the construction of the perforated ring member ofFigs'. 2 and 3.

Referring first to Fig. 1, -a mechanical treater is shown at 1 which consists of a series of cells located one above another and with rotary baffles carried by a verticall shaft. The oil to be treated and the sulphuric acid to be used in the treatment are supplied from the storage kor supply'tanks 2 and-3 respectively through pipes 4 and 5 having suitable regulating valves therein. Leading from the bottom of the treater is an outlet for the oil and acid tar which are pumped by the pump 6 and carried through the pipe 7 to the settling tank 8, or to-the first of a series of set-- tling tanks. In such settling tank or tanks the acid tar separates from the oil and the oil overflows through the pipe 11 either to another settling tank or to a receiving tank y12 for the acid-treated` oilwhile the acid sludge 10 collecting in the bottom of the settling tank is drawn o' and pumped to an acid recovery plant.

From the tank 12 the acid-treated oil passes through the pipe 13 to the mixing apparatus 17 and clay or fullers earth from the storage bin 14 is supplied vthrough the chute 15f and hopper 16 in regulated amount. The treated oil 1s thoroughly agitated with the fullers earth, and, when the treatment is complete, the oil and earth are pumped by the pump 19 through the line 20 to a pressure filter 21 from which the finished oil is discharged at 22. .In the treater 1 a series of rotary baii'ies 24 are carried by the shaft 25 which is driven by a pulley or other suitable mechanical means 26. These rotary baffles are arranged4 CJI mingle and arev thrown by centrifugal force against the walls of the apparatus and are thoroughly mixed, this intermixture being promoted .by the impact.`A The mingled oil and acidl then flow down the walls of the upper cell andare collected by the conical baille and delivered to the next lowerl disc, and this operation is repeated as the mingled oil and acid fiow downwardly through the treating apparatus. The repetition ofthe -intimate intermixture of the oil and acid during their passage downwardly through thel successive cells and over the successive baiiies brings about thorough treatment of the oil with the acid.v i

It will be evident that the size\and construction of the treater 1 can be varied and a sufficient number of cells and baffles provided to insure thorough intermixture and treatment of the oil with the acid so that the oil and acid sludge will finally be delivered to the outlet line of the treater and carried to the sludge settling tankor tanks ready for settling of the'acid sludge from the treated oil. In practice, a' series of settling tanks may be used, for example, three in number, to insure proper settling of the acid sludge from Vthe treated oil.

It is one advantage of the invention however that, because of the relatively mild, handling of the oil and acid in the treater, and the absence of oxidation by atmospheric air, the acid-treated oil and acid sludge are easily separated, andl clear settled oil readily obtained carrying only traces of impurities.

This acid-treated oil does not require a subsequent alkaline treatment, and it is a further advantage of the invention that such alkaline treatment can be eliminated.

For final purification of the acid-treated oil, a small amount of fullers earth or equivalent material, in a finely divided state, for example, of 100 mesh or finer, is added to the oil and thoroughly mixed therewith. Thus in the apparatus illustrated, the acid-treated oil is thoroughly agitated with a small amount of fine fullers earth in the mixer 17, and, when 'the earth treatment is complete, the combined oil and earth are withdrawn llO and passed through a pressure filter to separate the earth and impurities and to give the finished oil. y

In the treatment of the oil with acid, and also in the treatment ofthe acid-treated oil with fullers earth, the oil can be heated (by means not shown) and held at the required temperature. The pressure filter employed for removing the earth from the oil may be of any suitable type but is shown as a pressure filter of the leaf type. The press cake may be Washed in the filter to free it from oil, for example, by Washing out heavier oil with naphtha and by then removing the naphtha with steam, and the spent earth cake after such Washing and steaming operation may be removed from the press into a dump car 23 and discarded or restored by subsequenttreatment.

In Figs. 2 to 6 an improved form of treater 30 is shown of the same general type as the treater 1 of Fig. 1. The improved form of treater 30 of Fig. 2 has a central shaft 31 suitably mounted and supported therein and carrying a series of baffles 32. The outer shell of the treater carries side baffles 33 extending inwardly "andjdividing the treater into a series of cells similar to thoseof the treater of Fig. 1. Arranged Withinl each .cell is an annular ring 34 supported and spaced away from the sides of the cells by spacing and supportingmembers 36Yand having a series of holes extending therethrough of the shape and arrangement illustrated. The inlets for the oil and acid are indicated respectively' at 37 and,38 and the outlet for the treated oil and acid at 39.

The casing illustrated is made up-of two parts hinged together and with the two parts so constructed that the easing can be-bolted together to form in effect aunitary casing.

It will be noted that the rotating baflles 32 are shaped somewhat in the shape of a saucer so as to retard the escape of the acid and oil and bring about a more thorough intermixture. The shape and construction of the cell walls and the arrangement of the baffle rings 34 are alsov such as to promote thorough intermixture of the oil and acid.

It will be understood that the apparatus will be made of or lined with material resistant to the action of the acid and that the shape' and design and arrangement of the different parts of the apparatus canbe varied. The action however is suchthat the acid and oil are subjected to a most intimate and thorough intermixture While protecting the oil from oxidizing conditions such as arepresent when air agitation is employed. As a result such acid compounds as are formed in the oil are in such condition that they are readily Aremoved by the subsequent fineearth treatment and can therefore cause no inury in the finished oil.

The process will be further illustrated by the following specific example showing the treatment off.` reduced Bur-bank crude oil for the production therefrom of 650 F. fire test,

This oil was heated to a temperature of i 120 F. and was fed to the treater together with 66 B. sulphuric acid in the proportion of 13 lbs. of acid per barrel of oil. The oil and acid sludge mixture from the treater was settling tank, and the partially cleared oil rising to the topof this tank overflowed into a second settling tank, while liquid acid sludge settling at the bottom of the first settling tank was Withdrawn at intervals and stored for recovery of its acid content. The first settler. was held at a temperature of about 90 F.1while the top of the second sludge settling tank was held at about 120o F. and the bottom at about 90 F. by suitable heating devices. The clear oil from the second settling tank overflowed into the storage tank for the treated oil. y

- Suitable batches of the acid treated oil were drawn into the earth mixer and finely divided raw fullers earth of 100 mesh or finer p was added in the proportion of 4% by weight of the oil. Thev batch was warmed to 175 F. and thoroughly agitated by the power operated stirrer for a period of about 30 minutes until the treatment Was complete.

p The batch was then transferred, with the stirrer still in motion to keep the earth in suspension, to a filter 'press by means of a pump in order to separate the suspended earth from the treated oil. The piping was so arranged that the first runnings from the filter, which were somewhat cloudy. could be returned to the main batch. IVhen the stream from the filter press became clear it was cut into the storage tank for the treated oil.`

press cake was Washed with naphtha until free oil Wasremoved and the washing added to the original filtrate. When the press cake Was free of oil, steam was turned in to dry the earth mass and permit of easy discharge when the filter was opened. After dumping, the filter was ready for another cycle of operations. The spent earth from thefilter may be restored for use if desired. It will be evident that the size of the apparatus and the amount of oil treated can he varied. depending upon the amount of" oil requiring treatment, etc. It will also be evident that a series of smaller treaters can be used in place of a single large treater.

In the process of the above'cxample he oil was treatedwith a sludge loss of 7 .4% and a -yield of 92.6% obtained of an acid treated o1 of 31.7 gravity. After'the fullers earth At the end-of the filtering operation. the

lpumped continuouslyjto the first sludge treatment a yield of refined oil of 90.2% of the original stock was obtained in the form of the Ifiltrate and an additional 1.9% from the washings with a loss of only 0.5% with the The untreated crude oil was of a character which could not be satisfactorily refined by the established refining methods, but the oil refined in t-he manner above described was a high grade product adapted for steam distil-- lation for the production therefromof steam refined lubricating oil. From the treated oil on distillation a yield of 74.2% of gas oil was obtained of 33.6 gravity, and a yield of 17.3% of steam refined cylinder stock of 21.9 gravity, 570 F. flash point, 650 F.'fire point, a viscosity of 202 at 22t0o F., a pour test of 50,

of a full steam refined green color, with a carbon residue of 3.76%, an ash residue of 0.03% and an insoluble content in 86 naphtha of 0.078%. The complete refining and distilling operation was carried out with a treating loss of 7 4%, a filter loss of 0.5% and a distillation loss of 0.6%.

We have treated in a similar manner raw crude oils varying in quality from average pipe line mid-continental grade to the usual Pennsylvania grade with equally good results. The net loss on treating varies some'- `what with the quality of the oil, but the linished products are uniformly of high quality.

It will thus be-seenthat the present in- 4vention provides an improved method and apparatus for refining hydrocarbon oils which are of particular value in the refining of crudes or reduced cudes of middling grade, such as the average mid-continent Crudes or reduced crudes, for the production therefrom of refined oils which are adapted .for direct treatment 'by steam distillation for the recovery Of-high grade lubricating oils and other oils therefrom.

It will be evident that the invention presents many advantages. -Among these ad? vantages may be mentioned the following: The equipment required is compactand can be assembled in a relatively small space; the process is practically continuous and permits of large daily throughput; the regulation of the degree of treatment for agiven oil is simple, and no long periods of settling and washv vless cost per barrel thanby established methods; and the inventionmakes possible.

cording to t the production of oils of superior quality from raw materials which cannot be satisfactorily treated by established refinery methods, thus extending the field of oils from which high grade lubricants can be obtained'.

In its broader aspects, the invention, as above stated, is of moie or less general application; but we consider the invention to be of.J special value and application for the treatment of crude' oils or reduced crudos which cannot be rened with sulphuric acid according to ordinary methods, but which can be easil and satisfactorily refined acfie present invention to give refined oils which can be subjected to steam distillation for the recovery of high grade lubricating oils therefrom.

We claim:

1. An apparatus for the treatment of oil with sulphuric acid comprising a vertical treater having a series of superimposed cells therein, a series of imperforate disks arranged horizontally wit-hin the separate cells and mounted on a vertically disposed rotating shaft, inwardly extending bafHes between each of said disks, means for supplying streams of oil and acid to the 'upper end of the treater in regulated amounts, means to cause mixed streams of oil and acid to be repeatedly and successively distributed and `thrown outwardly against the cell walls in a thin nlm and means for removing the treated oil and acid from the treater in a continuous manner. l

2. An apparatus for the treatment of oil treater having a seriesof superimposed cells ranged horizontally within the separate cells and mounted on a vertically disposed rotating shaft, inwardly extending baffles between 4each of said disks, means for supplying streams of oil and acid to the upper end of the treater in regulated amounts, means to cause mixed streams of oil and acid to be repeatedly and successively distributed and with sulphuric acid comprising a vertical thrown outwardly against the cell walls in a thin film, means for removing the treated oil and acid from the treater in a continuous manner, means for separating the acid tar from the oil and means for subsequently subjecting the oil to treatment with afinely divided absorbent material.

3. An apparatus for the treatment of oil with sulphuric acid comprising a vertical treater having a serieshof superimposed cells therein, a series of imperforate disks arranged horizoiitallywithin the separate cells and mounted on a vertically disposed rotating shaft, inwardly extending baflies between each of said disks, means for supplying streams of oil and acid to ,the upper end of the treater in regulated amounts, means to cause mixed streams of oil and acid to be repeatedly and successively distributed and thrown out- CTI AWardlyk against the cell Walls in a thin film,

means for excluding air from the treater and means for removing the treated oil and acid from the treater in a continuous manner.

4'. The improvement in the refining of petroleum oils with sulphuric acid which comprises intermingling streams of the oil and the acid in regulatedamounts, rapidly rotating a disk while supplying a stream of the oil and acid mixture to the upper surface thereof, whereby the oil and acid mixture is distributed over the upper surface of said disk and discharged in a thin film of uniform thickness around the outer entire edge thereof, subjecting the -oil and acid mixture discharged from said disk to impact and/subsequently separating the acid tar from the oil.

5. The improvement in the refining of petroleum oils with sulphuric acid Which comprises interiningling streams of the oil and the acid in regulated amounts, rapidly rotating a disk while supplying a stream of the oil and acid mixture to the upper surface i thereof, whereby the oil and acid mixture is distributed over the upper surface of said disk and discharged in athin film of uniform thickness around the entire outer edge thereof," subjecting the oil yand acid mixture discharged from said disk to impact, and subsequently treating the oil with a finely divided absorbent material. v

6. T he improvement in the refining of p'etroleum oils with sulphuric acid which comprises intermingling streams of thev oil and the acid inv regulated amounts, rapidly rotating a disk while supplying a stream of the oil and acid mixture to the upper surface thereof, whereby the oil and acid mixture is .distributed over the upper surface of said disk and discharged in a thin film of uniform. thickness around the entire outer edge thereof, subjecting the oil and acid mixture discharged from said disk to impact, and excluding air from contact with the oil and acid mixture throughout the foregoin treatment.

7. The improvement in the re lng of petroleum oils with sulphuric acid which eomprises intermingling streams of the oil and i the acid in regulated amounts, rapidly roof, subjecting the oil and acid mixture discharged from said disk to impact, excluding air from contact With-the oil and acid mixture throughout the foregoing treatment and subsequently treating the oil with a finely cli-, vided absorbent material.

8. The improvement in the refining of petroleum oils Wit-h sulphuric acid which comprises intermingling streams of the oil and the acid in regulated amounts, rapidly rotating a disk while supplying a stream of thev oil and acid mixture to the upper surface thereof, whereby the oil and acid mixture is distributed over the upper surface of said disk and discharged in a thin film of uniform thickness around the entire outer edge thereof, subjecting the oil and acid mixture discharged from said disk to impact, sub- `sequently permitting the acid-treated oil to settle, and treatingthe resulting oil with a finely divided .absorbent material.`

9. The improvement in the refining of petroleum oils with sulphuric acid which comprises intermingling streams of the oil and the acid in regulated amounts rapidly rotating a series of Adisks While supplying a stream of the oil and acid mixture successively to the upper surfaces of each of said rotating disks, whereby the oil and acid mixture is distributed successively over the upper surfacesof each of said disks and discharged in thin films of uniform thickness around the entire outer edges thereof, subjecting the oil and acid mixture discharged from said'disks to impact and subsequently separating the acid tar from the oil.

In testimony whereof We affix our signatures.

ERNEST B. PHILLIPS. JAMES G. STAFFORD. 

